Methods for the control and optimization of a continuous bioreactor were developed. Specifically, the maximization of cellular productivity in a continuous bakers' yeast fermentation was considered. Four problems were dealt with: bioreactor start-up; finding the point of optimum cellular productivity; tracking the optimum as changes occur in the process; and bioreactor stability.;An adaptive on-line optimization method was developed which employed dynamic model identification. This method is attractive in the application to continuous bioreactors for the following reasons: very little a priori information is needed; it is easy to implement; it is faster than conventional methods; it adapts to changes in the process; and it is very stable. Computer simulations of the optimization of a continuous bakers' yeast fermentation were performed. These showed feasibility of the method and also yielded approximate values of tuning factors necessary for experimental implementation.;A versatile computerized fermentation system was developed to facilitate experimental investigations and to implement control and optimization schemes. The computerized fermentation system consists of two parts: a real-time computer control system; and a highly instrumented bioreactor with complete feedback capabilities.;Experiments were conducted which tested and compared various startup procedures for a continuous bakers' yeast fermentation. Oscillatory phenomena in continuous bakers' yeast fermentations was also investigated, particularly with respect to the dissolved oxygen control loop. Finally, the adaptive on-line optimization method was implemented experimentally. Results show that the method optimizes quickly, adapts to changes in the process, and is stable even with the occurrence of operational difficulties.
展开▼
